Bull Run is a stream in Northern Virginia that is best known for two military engagements that occurred there during the American Civil War. The first of these occurring 21 July 1861 was the first major military clash between the Union and Confederate (North and South) armies. The second battle lasted for three days and began on 28 August 1862. Both may be called the battle or battles of Bull Run, though the first is often referred to as the Battle of Manassas, and the second may also be known occasionally as the Battle of Groveton or second Manassas.
Often the first battle is known better because of its significance to the Union in terms of how it viewed the war and because of the way it lifted the confidence of the South. Many people in the North felt that the Union armies would quickly defeat the Confederacy, and there was great pressure exerted on the government and the army to move decisively against the Confederacy and end the war. On both sides, recruits to the armies were relatively untrained, but despite this, President Lincoln ultimately convinced Brigadier General Irvin McDowell to move his troops to Northern Virginia. It was hoped that cutting off access to the railroad below Bull Run would diminish the Confederate Army’s chances and leave the Union a clear path toward conquering the Confederate capital.
The march to Bull Run was slightly over 20 miles from where the troops were located, and there was little subterfuge in the march of over 30,000 men, which took two days. The Confederacy was well prepared for the arrival of the Union soldiers. The slow march was simply one indication of the inexperience of Union soldiers, and the loss of the battle was yet another. After heated fighting, the Union Army was forced to retreat with casualties exceeding the Confederacy's by about 1000 men.
For Northerners, the first Battle of Bull Run was ultimately discouraging. It disillusioned people in the Union who felt the South would be easy to beat. The fierceness with which the Confederacy had defended Bull Run meant a long engagement and long fight was ahead for both sides. The victory of the Confederacy did much to hearten the South for yet more fights.
The Second Battle of Bull Run was a much larger engagement, involving about 62,000 Union troops and 50,000 Confederate Troops. Casualties were enormous on both sides with over 3000 Union and Confederate deaths. Again, fortune favored the defending army instead of the attackers, and the Confederacy was able to defeat the Union. This again enlivened and raised Confederate hopes of an eventual victory.
Many of the historic battle sites of the Civil War have been preserved, and today people can visit Manassas National Battlefield Park. The country was even split, and sometimes remains so on what to call these battles. Bull Run remains a Northern name for the two engagements while the South may still favor calling them the first and second Manassas battles. The National Park Service has followed Southern conventions in this respect.